Colloidal silica composite films for premetal dielectric applications

Abstract

A colloidal suspension of nanoparticles composed of a dense material dispersed in a solvent is used in forming a gap-filling dielectric material with low thermal shrinkage. The dielectric material is particularly useful for pre-metal dielectric and shallow trench isolation applications. According to the methods of forming a dielectric material, the colloidal suspension is deposited on a substrate and dried to form a porous intermediate layer. The intermediate layer is modified by infiltration with a liquid phase matrix material, such as a spin-on polymer, followed by curing, by infiltration with a gas phase matrix material, followed by curing, or by curing alone, to provide a gap-filling, thermally stable, etch resistant dielectric material.

1. A method of forming a dielectric layer on a substrate comprising:
 depositing a colloidal dispersion on a substrate;  
 curing the colloidal dispersion to form an intermediate layer; and  
 infiltrating the intermediate layer with a matrix material to form an infiltrated layer.  
 
   
   
     2. The method of  claim 1 , wherein the colloidal dispersion comprises particles of a dense material dispersed in a solvent. 
   
   
     3. The method of  claim 2 , wherein the dense material comprises a dielectric material or a material convertible to a dielectric material by oxidation or nitridation. 
   
   
     4. The method of  claim 1 , further comprising curing the infiltrated layer. 
   
   
     5. The method of one of  claim 1  or  4 , further comprising baking at least one of the colloidal dispersion or the intermediate layer. 
   
   
     6. The method of  claim 5 , wherein baking comprises at least one bake step wherein the at least one bake step comprises a temperature in the range of about 75 to about 300° C. 
   
   
     7. The method of  claim 6 , wherein baking comprises at least two bake steps and wherein the bake steps comprise at least one temperature in the range of about 75 to about 300° C. 
   
   
     8. The method of one of  claim 1  or  4 , wherein curing comprises thermal processing, an annealing method or a combination thereof. 
   
   
     9. The method of  claim 8 , wherein the annealing method comprises electron beam annealing, ion beam annealing or a combination thereof. 
   
   
     10. The method of one of  claim 1  or  4 , wherein curing comprises a vacuum atmosphere. 
   
   
     11. The method of one of  claim 1  or  4 , wherein curing comprises an atmosphere of nitrogen, oxygen, nitrogen-bearing species, oxygen-bearing species, ozone, steam, ammonia, argon, carbon monoxide, carbon dioxide, nitrous oxide, nitric oxide, helium, hydrogen or mixtures thereof. 
   
   
     12. The method of  claim 11 , wherein the atmosphere comprises oxygen, nitrogen, oxygen-bearing species, nitrogen-bearing species or a combination thereof. 
   
   
     13. The method of  claim 1 , wherein the infiltrated layer is modified forming the dielectric layer. 
   
   
     14. The method of  claim 1 , wherein infiltrating the intermediate layer with a matrix material comprises infiltrating the intermediate layer with a coating solution of a spin-on polymer material. 
   
   
     15. The method of  claim 14 , wherein the spin-on polymer material comprises a material comprising silicates, hydrogen silsesquioxanes, organosilsesquioxanes, organosiloxanes, silsesquloxane-silicate copolymers, silazane-based materials, polycarbosilanes or acetoxysilanes. 
   
   
     16. The method of  claim 14 , wherein the spin-on polymer material comprises arsenic, antimony, phosphorous or boron. 
   
   
     17. The method of  claim 1 , wherein the particles of the dense material comprise silica, silicon, silicon nitride, silicon oxynitride, aluminum, aluminum nitride or aluminum oxide. 
   
   
     18. The method of  claim 17 , wherein the dense material further comprises a species comprising arsenic, antimony, phosphorous or boron. 
   
   
     19. The method of  claim 1 , wherein the particles have a characteristic dimension between about 2 nanometers and about 50 nanometers. 
   
   
     20. The method of  claim 1 , wherein the dielectric layer is a pre-metal dielectric layer on an integrated circuit device. 
   
   
     21. The method of  claim 1 , wherein the dielectric layer fills a trench in a shallow trench isolation structure. 
   
   
     22. The method of  claim 1 , wherein the dielectric layer fills gaps of dimension less than 100 nanometers. 
   
   
     23. The method of  claim 1 , wherein the dielectric layer is resistant to standard buffered oxide etchant solutions. 
   
   
     24. The method of  claim 1 , wherein infiltrating the intermediate layer with a matrix material comprises depositing a matrix material on the intermediate layer by chemical vapor deposition. 
   
   
     25. The method of  claim 1 , wherein infiltrating the intermediate layer with a matrix material comprises depositing a matrix material on the intermediate layer by atomic layer deposition. 
   
   
     26. The method of  claim 1 , wherein the matrix material comprises phosphosilicate glass, borosilicate glass or borophosphosilicate glass. 
   
   
     27. A dielectric material formed from the method of  claim 1 . 
   
   
     28. A dielectric material formed from the method of  claim 4 . 
   
   
     29. A component comprising the dielectric material of  claim 27 . 
   
   
     30. A component comprising the dielectric material of  claim 28 .